CONTROL KNOB, CONTROL SYSTEM AND HOUSEHOLD APPLIANCE

Abstract

A control knob for rotating a shaft in a household appliance, in particular for operating a valve shaft in a gas valve of a cooking hob. The control knob comprises: a knob element for manual operation by an operator, the knob element comprising an opening; and a coupling element made of light-transmitting material configured to send light through the opening towards the operator; the coupling element being configured to connect the knob element to the shaft in a rotationally fixed manner.

Claims

1-15. (canceled)

16. A control knob for rotating a shaft in a household appliance, in particular for operating a valve shaft in a gas valve of a cooking hob, the control knob comprising: a knob element for manual operation by an operator, the knob element comprising an opening; and a coupling element made of light-transmitting material configured to send light through the opening towards the operator, the coupling element being configured to connect the knob element to the shaft in a rotationally fixed manner.

17. The control knob of claim 16, wherein the coupling element is arranged at least partially inside or, with respect to the operator, behind the opening in the knob element.

18. The control knob of claim 16, wherein the knob element is at least partially made of a non-light-transmitting material.

19. The control knob of claim 16, wherein the opening is formed as a slit inside the knob element, the slit extending in a plane including an axis of rotation of the shaft or parallel thereto.

20. The control knob of claim 16, wherein the opening extends through an axial face and/or circumferential surface of the knob element.

21. The control knob of claim 16, wherein the knob element has a T-shaped cross section.

22. The control knob of claim 16, wherein the knob element comprises a base portion and a gripping portion axially protruding from the base portion.

23. The control knob of claim 16, wherein the coupling element comprises a sleeve portion for receiving the shaft along an axial direction so as to connect the knob element to the shaft in the rotationally fixed manner.

24. The control knob of claim 23, wherein the opening is formed as a slit inside the knob element, said coupling element comprising a plate shaped portion extending inside the slit in the knob element and configured to send out light through at least one edge of the plate-shaped portion, and a connecting portion connecting the plate shaped portion to the sleeve portion and arranged inside a recess in the knob element so as to transfer a rotational force acting on the knob element onto the coupling element.

25. The control knob of claim 24, wherein the plate shaped portion extends radially further than the connecting portion.

26. The control knob of claim 24, further comprising a single screw fixing the connecting portion to the knob element.

27. The control knob of claim 24, wherein the plate shaped portion, the connecting portion and/or the sleeve portion are formed integrally.

28. The control knob of claim 23, further comprising radial ribs connecting the sleeve portion to the connecting portion and/or a spring element inserted into the sleeve portion.

29. A manual control system for a household appliance, comprising: a control knob comprising a knob element configured for manual operation by an operator and comprising an opening, and a coupling element made of light-transmitting material configured to send light through the opening towards the operator; and a rotatable shaft coupled to the coupling element of the control knob by connecting the knob element to the shaft in a rotationally fixed manner.

30. The manual control system of claim 29 for use in a cooking hob as the household appliance.

31. The manual control system of claim 29, wherein the shaft is a valve shaft of a gas valve.

32. A household appliance, comprising: a control knob comprising a knob element configured for manual operation by an operator and comprising an opening, and a coupling element made of light-transmitting material configured to send light through the opening towards the operator; and a rotatable shaft coupled to the coupling element of the control knob by connecting the knob element to the shaft in a rotationally fixed manner.

33. The household appliance of claim 32, constructed in a form of a cooking hob.

34. The household appliance of claim 32, wherein the shaft is a valve shaft of a gas valve.

35. The household appliance of claim 32, further comprising a light source for emitting light towards the coupling element, wherein the coupling element is configured to guide the light emitted by the light source and to send it towards the operator through the opening in the knob element.

Description

[0057] Further embodiments, features and advantages of the present invention will become apparent from the subsequent description and dependent claims, taken in conjunction with the accompanying drawings, in which:

[0058] FIG. 1 shows a top view of one embodiment of a gas cooking hob;

[0059] FIG. 2 shows a perspective view of the gas stove according to FIG. 1;

[0060] FIG. 3 shows an exploded perspective view of the gas stove according to FIG. 1;

[0061] FIG. 4 shows a perspective view of one embodiment of a control knob for the gas stove according to FIG. 1;

[0062] FIG. 5 shows an example of a coupling element for the control knob of FIG. 4;

[0063] FIG. 6 shows a cross sectional view of a portion of the control knob of FIG. 4;

[0064] FIG. 7 shows a perspective view of another embodiment of a control knob for the gas stove according to FIG. 1; and

[0065] FIG. 8 shows an example of a spring for the control knob of FIG. 7.

[0066] In the Figures, like reference numerals designate like or functionally equivalent elements, unless otherwise indicated.

[0067] FIG. 1 shows a schematic top view of an embodiment of a gas cooking hob or gas stove 1.

[0068] FIG. 2 shows a schematic perspective view of the gas stove 1. FIG. 3 shows a schematic exploded perspective view of the gas stove 1. In the following, FIGS. 1 to 3 are referred to at the same time.

[0069] The gas stove 1 can be a household appliance or part of a household appliance. The gas stove 1 comprises a cooking trough 2. The cooking trough 2 is a deep-drawn metal sheet. The gas stove 1 further has at least one gas burner arrangement 3. The number of gas burner arrangements 3 is arbitrary. As FIG. 1 shows, there can be provided five gas burner arrangements 3.

[0070] Each gas burner arrangement 3 comprises a gas valve 4 which is attached to a main gas pipe 5, a gas burner 6 and a gas conduit 7 which connects the gas valve 4 to the associated gas burner 6. The gas valve 4 preferably is a gas regulating valve. The gas valve 4 is suitable for regulating a stream of combustion gas from the main gas pipe 5 to the gas burner 6 continuously or stepwise. In particular, the gas valve 4 is a so-called step valve. The gas valve 4 is preferably clamped to the main gas pipe 5.

[0071] A light source 30 is associated to the valve 4 for illuminating the control knob 13 from below. The control knob 13 ca be operated by the user of the gas stove.

[0072] The cooking trough 2 is covered by means of a cover plate or top sheet 8. The plate 8 covers the cooking trough 2. The plate 8 is a glass plate or a glass-ceramic plate. The plate 8 can also be made of metal, in particular stainless steel. The plate 8 has a front side (upper surface) 9 and a back side (bottom surface) 10. The front side 9 faces to a potential user of the cooking hob 1. The back side 10 is facing the cooking trough 2. The plate 8 comprises a number of breakthroughs (openings) 11. The number of breakthroughs 11 is the same as the number of gas valves 4. Each gas valve 4 has its own breakthrough 11. The breakthroughs 11 are cylindrical bores. In the following only one breakthrough 11 and only one gas valve 4 will be referred to.

[0073] The gas valve 4 is arranged below the plate 8. That means, the gas valve 4 faces the back side 10 of the plate 8. The gas valve 4 has a shaft (actuation stem) 12 which is guided through the breakthrough 11. In particular, the shaft 12 can be guided from the back side 10 to the front side 9 of the plate 8. However, the shaft 12 can end before the plate 8 so that it is not guided through the breakthrough 11. The shaft 12 can be rotated around an axis of rotation A to adjust the flow of combustion gas from the main gas pipe 5 to the gas burner 6. Depending on an angle of rotation of the shaft 12, the flow of combustion gas from the main gas pipe 5 to the gas burner 6 can be increased, decreased or completely blocked. An electronic board or circuit board (not shown) is arranged between the gas valve 4 and the plate 8. In use of the gas stove 1, the circuit board has to be protected from fluids like water or spilled food. The shaft 12 can be guided through the circuit board.

[0074] As can be seen in FIG. 4, each gas valve 4 has a control knob 13 for actuating the shaft 12. “Actuating” in this context, means rotating, in particular around the shaft rotation axis A. The control knob 13 comprises a knob element 14, which is manually operable 5 (rotatable) from the outside by an operator. The knob element 14 is preferably made of plastic. The knob element 14 can be made of acrylonitrile butadiene styrene (ABS), polypropylene (PP), polyethylene (PE) or any other suitable opaque plastic material. In embodiments, the knob element 14 is made of a metal material. The knob element 14 can be made by injection molding.

[0075] The knob element 14 has a base portion 15. The base portion 15 is cylinder shaped (circular cylinder). From an upper side of the base portion 15, a gripping portion 16 protrudes. The gripping portion 16 is bar-shaped. The gripping portion 16 can be gripped with two fingers to rotate the shaft 12. The gripping portion 16 and the base portion 15 are integrally formed.

[0076] Inside the knob element 14 a slit 19 forms an opening 17 in the knob element 14 and a recess 25 for partly accommodating a coupling element 18 of the control knob 13. The coupling element 18 is shown in a perspective view in FIG. 5. The coupling element 18 includes a sleeve portion 20 into which the shaft 12 is insertable. A sleeve interior 21 has a D-shape in cross section to engage with the shaft 12, which equally has a D-shape. Thereby, relative rotations between the shaft 12 and the coupling element 18 are prevented.

[0077] The coupling element 18 further includes a plate shaped portion 22 formed as a thin substantially rectangular plate which is insertable into the slit 19 of the knob element 14 such that edges 23 including a radial end portion 31 and an axial end portion 32 are visible to an operator through the opening 17. The shape of the slit 19 matches the shape of the plate shaped portion 22. The plate shaped portion 22 and the sleeve portion 20 are connected to one another through a connecting portion 24. The connecting portion 24 is thicker than the plate shaped portion 22. As shown in FIG. 4, the connecting portion 24 can be inserted into the recess 25 of the knob element 14. The only portion of the coupling element 18 that is not inserted inside the knob element 14 is the sleeve portion 20.

[0078] The sleeve portion 20, the connecting portion 24 and the plate shaped portion 22 of the coupling element 18 are formed integrally. They are all made of a light-guiding material comprising polycarbonate.

[0079] As shown in FIG. 2, the gas stove 1 includes a light source 30 arranged in the cooking trough 2. The light source 30 includes a plurality of LEDs which emit light towards the rotation axis A. The part of the sleeve portion 20 protruding from the connecting portion 24 being longer than the thickness of the plate 8, the sleeve portion 20 extends below the plate 8. There, it is located in the light path of the light emitted by the light source 30. The light emitted by the light source 30 is coupled into the sleeve portion 20 and guided through the sleeve portion 20, through the connecting portion 24, through the plate shaped portion 22 and finally through the opening 17 towards the operator. Since the opening 17 extends through an axial face 33 and through a circumferential surface 34 of the knob element 14, the operator can see the light output through those two sides 33, 34.

[0080] The light sent out through the opening 17 has a high intensity and homogeneity because an integrally formed coupling element 18 with an optimized shape is used. Further, the integrally formed coupling element 18 facilitates the assembly process of the control knob 13. In detail, the control knob 13 only comprises two elements to be assembled together: the coupling element 18 and the knob element 14. In the assembly process, the coupling element 18 is inserted into the knob element 14 as previously described. The plate shaped portion 22 is inserted into the slit 17 and the connecting portion 24 is inserted into the recess 25. Thereby, a relative rotation between the coupling element 18 and the knob element 14 is prevented. To axially fix the coupling element 18 to the knob element 14, a screw 26 is attached through a screw hole 27 of the coupling element 18 to the knob element. A relative axial displacement of the coupling element 18 relative to the knob element 14 is further avoided by means of a bridge portion 35, which maintains a part of the plate shaped portion 22 which axially extends further than the connecting portion 20 in place axially.

[0081] The fixing of the coupling element 18 to the knob element 14 is further shown in the sectional view of FIG. 6. FIG. 6 is a section of the control knob 13 of FIG. 4 along a plane of the plate shaped portion 22 and of the slit 19.

[0082] FIG. 7 shows a perspective view of another embodiment of a control knob 13 for the gas stove according to FIG. 1. The control knob 13 of FIG. 7 is identical with the control knob 13 of FIG. 4, except that it additionally includes ribs 18 and a spring portion 29 (further shown in FIG. 8). The ribs 18 are radial ribs arranged on an outer surface of the sleeve portion 20 and on the connecting portion 24, thereby strengthening the connection between the sleeve portion 20 and the connecting portion 24. The spring 29 is a metal spring with a D-shaped cross section which is arranged on the interior 21 of the sleeve portion 20 to strengthen the sleeve portion 20.

[0083] Although the present invention has been described in accordance with preferred embodiments, it is obvious for the person skilled in the art that modifications are possible in all embodiments. For example, the knob element 14 may have a cylindrical shape, without gripping portion 16. The opening 17 may extend only along the axial face 33 or along the circumferential surface 34, or there may be several openings in the knob element 14 for outputting light. The shape of the coupling element 18 may be adapted accordingly. Further, instead of the sleeve portion 20, the coupling element 18 may include an axis to be engaged with a sleeve-shaped shaft 12.

REFERENCE NUMERALS

[0084] 1 gas stove [0085] 2 cooking trough [0086] 3 gas burner arrangement [0087] 4 gas valve [0088] 5 main gas pipe [0089] 6 gas burner [0090] 7 gas conduit [0091] 8 plate [0092] 9 front side [0093] 10 back side [0094] 11 breakthrough [0095] 12 shaft [0096] 13 control knob [0097] 14 knob element [0098] 15 base portion [0099] 16 gripping portion [0100] 17 opening [0101] 18 coupling element [0102] 19 slit [0103] 20 sleeve portion [0104] 21 sleeve interior [0105] 22 plate shaped portion [0106] 23 edge [0107] 24 connecting portion [0108] 25 recess [0109] 26 screw [0110] 27 screw hole [0111] 28 rib [0112] 29 spring element [0113] 30 light source [0114] 31 radial end portion [0115] 32 axial end portion [0116] 33 axial face [0117] 34 circumferential surface [0118] 35 bridge portion [0119] A rotation axis